moving three phase.

[rosscohans]

hi, im an electrician whos working at an office/shop referb. theres an existing three phase supply which was doing shop and office only using single phase. theres going to be a wall dividing the two. needing new board for shop. as office only needs two of the single phases say blue and yellow is there any way the sse can use the remainder phase red for the shop and put it on its own meter? this was very unexpected and now holding up job. as i cant touch sse side and waiting for them. has anyone got an idea what they would say? person on phone was talking about running new supply just for shop but this would be very exspensive.

 

[Knobhead]

How is it metered now just a single phase or three phase meter?

 

[malcolmsanford]

I know it is just an office but I would be very suprised if the SSE would meter just 2 phases into a premisis. They may advise the supplier to meter in 3 single phase meters and leave the rest up to you how you design the installation from there.

I have to admit apart from very old installations in rural areas mainly, I can't remember seeing a 2 phase installation for years.

 

[Knobhead]

See what you mean I can’t see them being keen on two phases in to one office at all. I get horrible visions of equipment on different phases side by side.

 

[Engineer54]

Why would an office/shop split need 2 separate phases in the office section?? The square metre age of floor area, would need to be quite substantial for such requirements... I'd be betting that 2 single phase supplies one for shop and one for office, is all that is needed here...

I've known quite a few instances where the DNO have just taken tails out of the 3 phase cut-out head, to say the single 1PH meter, or the two 1 PH meters that are required.... If the meter location is going to remain at it's present position, i can't see a problem!! If the supply to the office needs to be repositioned within the office area, extended CU/meter tails need to be thought about etc....

 

[Knobhead]

I personally would get the DNO to install an external meter box using the existing cable and have two meters and isolators fitted. You can sort the internals from there.
As to cost that’s in the lap of the gods (the DNO).

 

[Knobhead]

See the sticky http://www.electriciansforums.net/e...al-forum/36671-dno-earthing-arrangements.html in the general section there a link to supply requirements in post 4